In a trickling biological filter, the BOD value of the feed stream is S_0i = 500 mg/l with a feed flow of F = 10³ l/h. The effluent BOD value is desired to be S₀ = 10 mg/l. The following kinetic parameters for the biocatalysts are known: r_m = 20 mg/S/l .h and K_s = 200 mg S/l. The biofilm thickness is L = 0.1 mm. The cross-sectional area of the filter is A = 2 m² , and the biofilm surface area per unit volume of the bed is a = 500 cm² /cm³ . Assume that dissolved oxygen is the rate-limiting substrate and the diffusion coefficient of oxygen is D_O2 = 2 × 10^-5 cm² /s. Determine the required height of the bed. You can assume first-order bioreaction kinetics?

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TLS Online TPP Program

#Question id: 15614

#Section 1: Engineering Mathematics

TLS Online TPP Program

#Question id: 15623

#Section 4: Fundamentals of Biological Engineering

Under unaerated condition in a fermentor, the power consumed by a single impeller was 10,000 W. The diameter of the impeller D is 1m and the density of the medium is 1000 kg/m3 and the stirrer speed is 1s^-1. If one more impeller is added to the fermentor, power consumption would be approximately

TLS Online TPP Program

#Question id: 15624

#Section 4: Fundamentals of Biological Engineering

In heat transfer through a heat exchanger in co- current or counter-current flow, which of the assumptions is not correct ?

TLS Online TPP Program

#Question id: 15625

#Section 4: Fundamentals of Biological Engineering

A stagnant liquid film of 0.4 mm thickness is held between two parallel plates. The top plate is maintained at 400C and the bottom plate is maintained at 300C. If

the thermal conductivity of the liquid is 0.14 W/(m K), then the steady state heat flux ( W/m²) assuming one-dimensional heat transfer is

TLS Online TPP Program

#Question id: 15626

#Section 4: Fundamentals of Biological Engineering

In a mass transfer system the unit of diffusivity is

TLS Online TPP Program

#Question id: 15627

#Section 4: Fundamentals of Biological Engineering

A fermentation medium is being cooled from 70^0C to 32^0C in a double pipe heat exchanger. Fluid flowing counter currently with this stream in heated from 20^0C

to 46^0C. The log mean temperature difference (in0C) for the two streams is